The invention relates to a road test simulator.
In order to inspect a vehicle after its final assembly, various tests are ordinarily conducted. These tests are often carried out as actual road tests, which renders the testing costly.
So as to abbreviate or to completely replace such costly road tests, it is known in the art to provide a road test simulator, which can be used to simulate the irregularities of a road surface. Most prior-art simulators, however, have rollers with a non-adjustable profile. As a result they are inflexible and thus suitable only for limited testing of a vehicle.
A road test simulator with profiled rollers is known from German reference DE 299 18 490.0. Each of these rollers is provided with a plurality of profile-imparting blocks along its outer circumference. These blocks can be adjusted in the radial direction of the roller to change the profile of the roller. Each roller ranges in width from a single to a double width of the vehicle tire. The road test simulator is additionally provided with a computer unit to implement a test program. With the aid of this test program, the computer unit can be programmed, for example, to simulate different road surfaces automatically by adjusting the blocks of the rollers.
Published European Application EP 0 507 631 A discloses a method and an apparatus for testing two or four wheel drive vehicles under simulated road conditions. One embodiment, depicted in FIG. 5 of that reference, relates to a testing apparatus that has a separate roller for each wheel of a test vehicle. Each roller is associated with a separate power supplying and/or absorbing unit that is preferably equipped with a DC motor.
Further, German Laid Open Publication DE 37 44 631 A discloses a method and an apparatus for conducting vehicle life tests. FIG. 4 of this publication also shows an arrangement with a separate drum for each vehicle wheel. The bearing units for the drums are displaceable in longitudinal and transverse vehicle direction in order to adjust them to the wheelbase and the wheel gauge of the test vehicles. As in brake test stands, the inert mass of the drums is adapted to the mass of the vehicle, especially to simulate acceleration and braking on the test stand.